Negotiators at climate talks in Bali on Friday struggled to break a deadlock over US objections to goals for cutting emissions by dropping a reference to a non-binding 2020 target in draft text.

But the European Union insisted the two-week talks, due to end on Friday, should set stiff 2020 guidelines for rich nations to cut greenhouse gas emissions despite US opposition.

The 190-nation Bali talks are seeking the ground rules for launching two years of negotiations for a global pact to fight climate change to succeed the Kyoto Protocol after its first phase ends in 2012.

"We continue to insist on including a reference to an indicative emissions reduction range for developed countries for 2020," European Environment Commissioner Stavros Dimas said.

"Let me underline once again that the Bali roadmap must have a clear destination," he said. He did not restate, however, an EU demand for a reference to cuts of 25 to 40 percent cuts below 1990 levels by 2020.

A copy of the latest compromise draft, obtained by Reuters, retains an ambition for global greenhouse gas emissions to peak in the next 10-15 years and to fall well below half of 2000 levels by 2050. But it drops the 25-40 percent range for rich nations by 2020.

Another suggested text, however, retains a 25 to 40 range for 2020. The texts, drafted by hosts Indonesia for debate by environment ministers on Friday, say developed countries should take the lead in driving cuts in emissions of planet-warming greenhouse gases.

The European Union wants a range to guide talks on a pact to succeed the Kyoto Protocol beyond 2012 and to prove to poor nations such as China and India that the rich countries are committed to leading.

It was not clear if the United States and other countries would agree to either text. The United States, the world's top emitter of greenhouse gases, says any emissions goals in the final text would prejudge the outcome of talks.

UN Secretary-General Ban Ki-moon said delegates had "a political and historical responsibility" to reach a deal on a global climate pact by late 2009.

The United Nations wants the Bali talks to launch formal negotiations on a deal to succeed the Kyoto Protocol, to be agreed by 2009, as the world faces rising seas, more extreme droughts and floods and spread of disease.

Two years would also give governments time to ratify the new deal by the end of 2012 and give markets clear guidelines on how to make investments in clean energy technology.

The EU wants an emissions goal in Bali to give certainty to its rapidly growing carbon trading scheme. The 27-nation bloc has already committed to emissions cuts by 2020.

Green groups criticised the United States.

"The US is behaving like passengers in first class in a jumbo jet who believe that a catastrophe in economy class will not affect them," said Tony Juniper of Friends of the Earth International. He added: "If we go down, we go down together."    

Kyoto caps greenhouse gas emissions of all industrial nations except the United States until 2012.

Developing nations are exempt from Kyoto's 2008-2012 first phase and say that before they sign up to any broader agreement, rich countries, particularly the United States as the world's top greenhouse gas emitter, should take the lead in cuts.

On other issues, the Bali talks made progress on Friday by agreeing steps to slow deforestation. Trees store carbon dioxide as they grow.

"The agreement on deforestation is a good balance between different countries views and is one of the substantial achievements of this conference," Dimas said.

He said the agreement launched pilot projects, which would tackle deforestation and forest degradation, and contribute harder proposals in a broader climate pact in 2009.

Despite opposition to Kyoto, the United States plans to join a new trea